condition mean min max ZT0-3 764.381991 764.381991 764.381991 ZT4-7 691.2532054999999 691.2532054999999 691.2532054999999 ZT8-11 713.5395880000001 713.5395880000001 713.5395880000001 ZT12-15 790.9760695 790.9760695 790.9760695 ZT16-19 788.8768265000001 788.8768265000001 788.8768265000001 ZT20-23 906.568794 906.568794 906.568794